Vaccines that elicit cellular immune responses against viruses seek to reflect global viral diversity in order to effectively treat or prevent viral infection. For HIV vaccines, the initiation of robust and diverse human immunodeficiency virus (HIV)-specific T cell responses is desirable for an effective HIV vaccine. The highly variable Envelope protein (Env) is the primary target for neutralizing antibodies against HIV, and vaccine antigens may be tailored accordingly to elicit these antibody responses. To this end, immunogens mimicking the trimeric structure of Env on the native HIV virion are actively being pursued as antibody-based HIV vaccines. However, it has proven difficult to produce biochemically stable trimeric Env immunogens that elicit diverse neutralizing antibody responses.
Thus, there is an unmet need in the field for the development of vaccines that include novel, optimized trimeric Env immunogens, which can elicit a broad immune response (e.g., a broadly neutralizing antibody response) in order to allow for more successful HIV vaccination outcomes.